第十一篇：Spring Boot整合MyBatis

什么是 MyBatis ？

MyBatis 是一款优秀的持久层框架，它支持定制化 SQL、存储过程以及高级映射。MyBatis 避免了几乎所有的 JDBC 代码和手动设置参数以及获取结果集。MyBatis 可以使用简单的 XML 或注解来配置和映射原生信息，将接口和 Java 的 POJOs(Plain Old Java Objects,普通的 Java对象)映射成数据库中的记录。

引入依赖

在pom文件引入mybatis-spring-boot-starter的依赖：

<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>

<version>1.3.2</version>

</dependency>

引入数据库连接依赖：
 <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
 </dependency>

引入数据源

spring.datasource.url=jdbc:mysql://localhost:3306/test?zeroDateTimeBehavior=convertToNull&useUnicode=true&connectTimeout=5000&socketTimeout=5000&characterEncoding=UTF-8&useConfigs=maxPerformance&prepStmtCacheSqlLimit=1024
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

创建数据库表

建表语句：

CREATE TABLE `t_user` (
  `id` int(32) NOT NULL AUTO_INCREMENT,
  `name` varchar(20) NOT NULL,
  `age` int DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;
INSERT INTO `account` VALUES ('1', 'aaa', '25');
INSERT INTO `account` VALUES ('2', 'bbb', '25');

INSERT INTO `account` VALUES ('3', 'ccc', '25');

具体实现

这篇文篇通过注解的形式实现。

创建实体：

package org.springboot.sample.domain;

public class User {

    private Long id;
    private String name;
    private Integer age;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

}

dao层

package org.springboot.sample.domain;

import java.util.List;

import org.apache.ibatis.annotations.*;

@Mapper
public interface UserMapper {

	@Insert("insert into t_user(name, age) values(#{name}, #{age})")
	int add(@Param("name") String name, @Param("age") int age);

	@Update("update t_user set name = #{name}, age = #{age} where id = #{id}")
	int update(@Param("name") String name, @Param("age") int age, @Param("id") int id);

	@Delete("delete from t_user where id = #{id}")
	int delete(int id);

	@Select("select id, name as name, age as age from t_user where id = #{id}")
	User findUser(@Param("id") int id);

	@Select("select id, name as name, age as age from t_user")
	List<User> findUserList();

}

service层

package org.springboot.sample.service;

import java.util.List;

import org.springboot.sample.domain.User;
import org.springboot.sample.domain.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class UserService {
	@Autowired
	private UserMapper userMapper;

	public int add(String name, int age) {
		return userMapper.add(name, age);
	}

	public int update(String name, int age, int id) {
		return userMapper.update(name, age, id);
	}

	public int delete(int id) {
		return userMapper.delete(id);
	}

	public User findUser(int id) {
		return userMapper.findUser(id);
	}

	public List<User> findUserList() {
		return userMapper.findUserList();
	}
}

controller层，构建restful API

package org.springboot.sample.web;

import java.util.List;

import org.springboot.sample.domain.User;
import org.springboot.sample.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/user")
public class UserController {

	@Autowired
	UserService userService;

	@RequestMapping(value = "/list", method = RequestMethod.GET)
	public List<User> getUsers() {
		return userService.findUserList();
	}

	@RequestMapping(value = "/{id}", method = RequestMethod.GET)
	public User getUserById(@PathVariable("id") int id) {
		return userService.findUser(id);
	}

	@RequestMapping(value = "/{id}", method = RequestMethod.PUT)
	public String updateUser(@PathVariable("id") int id, @RequestParam(value = "name", required = true) String name,
			@RequestParam(value = "age", required = true) int age) {
		int t = userService.update(name, age, id);
		if (t == 1) {
			return "success";
		} else {
			return "fail";
		}

	}

	@RequestMapping(value = "/{id}", method = RequestMethod.DELETE)
	public String delete(@PathVariable(value = "id") int id) {
		int t = userService.delete(id);
		if (t == 1) {
			return "success";
		} else {
			return "fail";
		}

	}

	@RequestMapping(value = "", method = RequestMethod.POST)
	public String postUser(@RequestParam(value = "name") String name, @RequestParam(value = "age") int age) {

		int t = userService.add(name, age);
		if (t == 1) {
			return "success";
		} else {
			return "fail";
		}

	}

}

通过postman测试通过。

源码下载：https://gitee.com/zhmal/spring-boot-samples/tree/master/spring-boot-sample-mybatis